Field of the Invention
The present invention relates to an image processing apparatus, a method for controlling the image processing apparatus, and a storage medium.
Description of the Related Art
In an image processing apparatus such as a digital copying machine, it has been an important issue to reduce mechanical costs while improving productivity. As one of solutions for such an issue, a technique for increasing a document reading speed of a scanner at the time of copying is discussed (refer to Japanese Patent Application Laid-Open No. 2010-278870). Although increasing the document reading speed of a scanner decreases a resolution for document reading, improving the document image reading speed per unit time enables improving productivity.
As methods for reading a document by using a scanner, the following two different methods are generally used.
(1) a pressing plate reading method in which a document placed on a glass plate (document positioning plate) is read while an optical reading apparatus is being moved along with the document
(2) a document feeding-reading method in which each document is conveyed from a document bundle placed on a dedicated tray and then read by a fixed optical reading apparatus while the document is being conveyed
When switching the reading speed (more specifically, when changing the resolution), an image processing apparatus capable of reading a document by using the above-described two different methods generally uses the document feeding-reading method. This is because the document feeding-reading method in which the document conveying speed is changed achieves the reading speed switching at a lower cost than the pressing plate reading method in which an optical reading apparatus needs to be moved at variable speeds.
The document feeding-reading method performs the reading speed switching (more specifically, resolution switching) through an operation by a user. For example, when the user performs an operation for changing a read setting from a “speed priority” (speed is given priority) to an “image quality priority” (image quality is given priority) or vice versa, the reading speed in the document feeding-reading method is changed in response to this operation. The user changes the reading speed in the document feeding-reading method, taking into consideration a balance between the productivity at the time of copying and the quality of a printed image.
Conventionally, a copy function is provided with a continuous read function with which a document is read by switching between the pressing plate reading and the document feeding-reading methods, and then image data read by the pressing plate reading method and image data read by the document feeding-reading method can be printed as a set of image data.
However, when the above-described continuous read function is used, if the reading speed in the pressing plate reading method differs from that in the document feeding-reading method, the resolution of image data read by the pressing plate reading method differs from that of image data read by the document feeding-reading method. Therefore, in a printed product, a difference in image quality will arise between a page read by using the pressing plate reading method and a page read by using the document feeding-reading method.
To avoid such a situation, it was conventionally necessary to perform the above-described reading speed switching operation according to the copy function specified by the user. For example, when using the above-described continuous read function and when the reading speed setting for the document feeding-reading method differs from that for the pressing plate reading method, the user needed to perform an operation so that the reading speed in the document feeding-reading method coincides with that in the pressing plate reading method.
However, it is troublesome for the user to perform an operation for changing the reading speed in the document feeding-reading method taking such a setting into consideration each time the continuous read function is used. This will apply a load of operation to the user. A user who does not know about the above-described issue may not recognize even the necessity of taking the above-described reading speed into consideration, and accordingly may use the continuous read function without taking the above-described setting into consideration. As a result, a difference in image quality occurred between read pages, and there was a possibility that the user was unable to obtain an intended output product.